High-Capacity, Microporous Cu[sub 6]Sn[sub 5]–Sn Anodes for Li-Ion Batteries

Three-dimensional, microporous Cu 6 Sn 5 – Sn architectures were created by electrodeposition of copper and tin onto sintered copper foam substrates and evaluated as anodes for lithium-ion batteries. The electrodes were characterized before and after cycling by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectrometry. Before cycling, the electrochemically deposited films consisted of a combination of crystalline Cu 6 Sn 5 and Sn, whereas after cycling, the films appeared amorphous to X-rays. When evaluated in coin cells against metallic lithium, the composite Cu 6 Sn 5 – Sn electrodes delivered a reversible capacity of 670 mAh ∕ g , which is significantly greater than the capacity achieved previously from powdered (ballmilled) and thin-film (sputtered) Cu 6 Sn 5 electrodes, typically 200 – 350 mAh ∕ g .